The present invention relates to a filter and filter housing for use in a waste water treatment system and more particularly relates to a sectionalized filter housing having capability of receiving filter cartridges of various lengths and is adaptable for connecting to water treatment tank outlet pipes of varying diameters.
In the treatment of waste water, particularly in septic tanks, it is common to install filters to remove particulates being discharged from the tank which are generally undigested solids so that the discharging effluent is a relatively colorless and harmless liquid. There have been a number of filter units designed over the years for the removal of these undigested solids from the waste water prior to discharge from a septic tank or the like. For example, U.S. Pat. Nos. 2,900,084; 3,332,552; and, 4,710,295 to Robert Zabel teach a waste water treatment filtration system which includes a plurality of disc-dam units disposed in a stack, vertically spaced, in a super-imposed relationship such that the bottom of each overlying disc-dam unit cooperates with the upper edges of each underlying unit to form a horizontally elongated vertically narrow outlet slots. The stack of disc-dam units are mounted in a cylindrical housing with several slots located above and several slots located below the liquid operating level in a waste water tank. In operation, the digested waste water is received through a bottom opening of the housing and the discharging clarified effluent flows through a sidewall outlet which is in flow communication with an outlet from the waste water tank. However, it has been found that septic tanks or waste water treatment tanks come in different sizes and capacities and also the outlet discharge from the waste water tank is not of a standard size. Thus, for residential and commercial applications it is difficult to provide a filter housing unit of varying filtration capacities and with discharge outlets adaptable to mate with the various sizes of outlet discharge pipes or conduits from the waste water treatment tank.
It is an object of the present invention to provide a filter housing for a waste water treatment tank that includes a plurality of vertically extending interchangeable sections which allows for the design of a filter housing providing for a filtration system of different filtering capacities.
It is another object of the present invention to provide a filter housing have an outlet which is adaptable for mating with waste water treatment tank outlets of different sizes.
It is a further object of the present invention to provide a filter housing which is relatively inexpensive and easy to install.
It is even a further object of the present invention to provide a filter cartridge of disc-dam filter units in a filter housing that reduces turbulence during the upflow of waste water in the cartridge.
It is also an object of the present invention to provide a filter cartridge of disc-dam filter units wherein the discs have a diameter of less than xe2x85x9xe2x80x3 of the inside diameter of the filter housing.
More particularly, the present invention provides a filter and a housing for a waste water treatment system wherein the housing includes at least an upper section with an outlet for flow communication with a waste water treatment tank discharge outlet and a lower section with an open bottom to receive upward flow therethrough. The upper section is mounted above the lower section and there may be a plurality of middle sections mounted between the upper section and the lower section to accommodate filter cartridges of various lengths. Each of the sections of the housing include means to receive a plurality of disc-dam units therein. The plurality of disc-dam units in a stack arrangement define the filter cartridge with a longitudinally extending axis. Each of the disc-dam units is of a generally circular-shaped disc having an outer terminating edge, the base portion of each unit having a planar under surface and an upper surface with a first dam of serpentine configuration having a first and second terminating end. The dam which extends upwards from the upper surface of the base portion terminates in a dam top whereby a preselected distance is defined between the dam top and the under surface of an overlying disc. The first end and the second end of the dam define a cord segment therebetween, the dam dividing the base portion into an upstream and downstream side, the upstream side being along an outer periphery of the base portion and the downstream side being along an inner periphery of the base portion. The cord segment provides a cut out which extends from a second dam which connects the first and second ends of the outer terminating edge of the first dam wherein the second dam has a height less than the height of the first dam. Moreover, each of the discs are provided with a plurality of upstream openings in the upstream side of the base portion which are in flow communication with an adjacent underlying disc-dam unit. The flow through openings are generally positioned within the serpentine configured dam. The cut-outs of each disc are aligned to form an outlet flow chamber which is in flow communication with an outlet waste water treatment tank discharge outlet.
The lower section of the housing is provided with an inwardly extending sealing edge positioned for alignment with the disc-dam unit cut outs. The sealing edge is in contacting relation with the lowermost disc-dam unit wherein the sealing edge covers the cut out of the lowermost disc-dam unit thereby sealing the bottom of the outlet flow chamber from the incoming waste water to be filtered.